Burglar alarm



Jan. 20, 1953 w. w. FLUGRATH 2,625,901

BURGLAR ALARM Filed Sept. 12, 1949 Walter W. F/ugrafh INVENTOR.

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Patented Jan. 20, 1953 UNITED STATES PATENT OFFICE 1 Claim.

The present invention relates to new and useful improvements in burglar alarms and more particularly to a spring-actuated bell clapper held inactive by a locking mechanism and which is released by the opening movement of a door or the like.

An important object of the invention is to provide both a manually controlled and an automatically controlled locking mechanism for the bell clapper for rendering the alarm mechanism inoperative when desired, to permit the door or other alarm releasing medium to be freely opened and closed at will without sounding the alarm.

Another object is to provide an alarm which may be easily and quickly installed in position on a door frame without necessitating any changes or alterations therein, and which, at the same time, is simple and practical in construction, efficient and reliable in operation, neat and attractive in appearance, relatively inexpensive to manufacture and otherwise well adapted for the purposes for which the same is intended.

Other objects and advantages reside in the details of construction and operation as more fully hereinafter described and claimed, reference being bad to the accompanying drawings forming part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure l is a perspective view showing the alarm mounted in position on a door frame;

Figure 2 is an enlarged top plan view of the alarm;

Figure 3 is a sectional view taken on a line 3--3 of Figure 2;

Figured is an enlarged transverse sectional view taken on a line 4-4 of Figure 2 Figure 5 is an enlarged sectional view taken on a line 5--5 of Figure 2; and

Figure 6 is an enlarged perspective view of the manual locking means for the clapper.

Referring now to the drawing in detail, wherein, for the purpose of illustration, I have disclosed a preferred embodiment of my invention, the numeral 5 designates the alarm casing which is open at its top and formed at its upper edge with attaching flanges 6 for attaching to the under side of the header 1 of a door frame. The casing is also provided with removable sides 8 held in position by bolts 9.

A frame Ill is secured to sides 8 of the casing by bolts II, the frame including a pair of side frame members |2 secured together by bolts or the like l3 having spacing sleeves I4 to hold the sides of the frame spaced from each other.

A key-wound spring motor l5 of a conventiona1 type is supported in frame l0 and includes a spring-driven gear l6 engaging a pinion l1 secured to a shaft I8 journaled in frame ID.

A toothed escapement wheel I9 is also secured to shaft I8 and is alternately engaged by a pair of lugs on a clapper or bell hammer arm 2| which is fixed to a pin 22 slidably and rotatably supported in frame l0 and which projects outwardly of the casing and is provided with a knob 23.

Pin 22 is formed with a pair of annular grooves 24 in which the free end of a resilient finger 25 is selectively seated, the finger being fixed at its other end to one of the spacing sleeves M.

An extension 26 projects rearwardly from clapper arm 2| and is provided with a lateral stop 21 movable into and out of engagement with a stationary stop 28 attached to frame l0 when pin 22 is moved inwardly or outwardly, to thus lock clapper arm 2| and escapement wheel l9, when desired.

The escapement wheel I 9 is also locked to hold shaft l8 and clapper 2| inactive by means of a lug 30 on a bar 3| sliding in frame In and havin one end slidable in casing 5 to project outwardly at both sides thereof and provided at its outer ends with push and pull buttons 32 to manually lock the alarm.

A rod 33 extends downwardly from bar 3| in the path of a rod 34 extending horizontally from one side of a bar 35 which is also slidable in frame It] and projects outwardly at one side of easing 5. A coil spring 36 is held under tension on bar 35 between frame Ill and rod 34 to project bar 35 and to normally hold lug 3|) disengaged from escapement wheel l9.

A bell 31 is supported on frame ID in position to be struck by clapper 2|.

In the operation of the device, casing 5 is attached to the under side of header 1 of a door frame and with bar 35 positioned toward the outside of the door frame for engagement by a screen or other door 38 to push bar 35 inwardly when the door is closed. Knob-s 23 and 32 are positioned at the inner side of the door frame for manual actuation without interference by the door.

Knob 23 is pushed inwardly while spring motor I5 is being wound to move stop 21 in engagement with stop 28 to prevent movement of clapper arm 2| and escapement wheel l9.

When the alarm is set for sounding by an opening of the door, knob 23 is pulled outwardly, releasing stop 21, and knob 32 is also pulled outwardly, which then locks escapement wheel I9 by engaging lug 30 011 bar 3| with the wheel. As soon as the door is opened, spring 36 will move bar 35 outwardly, carrying pin 34 with it, which also moves pin 33 in a direction to slide bar 3! inwardly and. releases lug 30 from escapement wheel H] to set the clapper arm 2| in motion and sound the alarm.

Having described the invention, what is claimed as new is:

A closure alarm comprising a spring motor, a bell, a bell clapper pivotally mounted for oscillation to ring the bell, an escapement mechanism operative in conjunction with said motor to oscillate the clapper and including a toothed escapement wheel, an escapement wheel lock comprising a, slidably mounted bar movable into unlocking position, a spring projected 'slidably'mou'nted member held in retracted position by said closure and released for projection by opening of the closure, and means operatively connecting said member to said bar for moving said bar into rod on said bar, and a rod on said member for engagement with one side of the first named rod.

WALTER W. FLUGRATH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 72,786 Blakeslee et al Dec. 31, 186'? 256,145 Knight Apr. 11, 1882 386,045 Umbenhaur July 10, 1888 623,019 Holloman Apr. 11, 1899 732,727 Fletcher July '7, 1903 1,256,504 Mott et a1 Feb. 12, 1918 1,283,282 Papapavlou Oct. 29, 1918 1,854,126 Ferguson Apr. 12, 1932 2,360,589 Schlenker Oct. 17, 1944 2,447,526 Olvis Aug. 24, 1948 2,469,528 Suma May 10, 1949 FOREIGN PATENTS Number Country Date 494,424 Germany Apr. 7, 1930 605,135 France Feb. 13, 1928 

